The aim of this study is to find the acoustic characteristics of Korean stop consonants in the children from multicultural families and to delineate the effect of the mothers’ nationalities in multicultural families. Thirty children was participated in this study. The children were between the ages of four and six and had grown up in monolingual families and multicultural families with mothers from China and the Philippines. A picture naming test containing stop consonants was asked to children with simultaneous sound recording. VOT (voice onset time), vowel duration following consonants, release burst intensity, and the total duration of words were analyzed using a multi-speech program. The results are as follows: (1) The VOT of glottalized stops and aspirated stops is significantly different between children in monolingual families and children in multicultural families. (2) The release burst intensity of glottalized stops and aspirated stops is significantly different between the two groups (monolingual and multicultural children). (3) The total duration of words and the articulation time of vowels following consonants are not significantly different between the two groups (monolingual and multicultural children). In conclusion, the acoustic characteristics of Korean stop consonants have a triple opposition system: lenis, glottalized, and aspirated. However, the children of multicultural families have errors with the laryngeal gesture of stop consonants. The differences of acoustic characteristics between monolingual and multicultural children reflect the effect of the mothers’ nationalities.